[gtk+] Update gtk_drag_highlight() docs

[Matthias Clasen <matthiasc src gnome org>]

commit ec5baa144d30b0affc0917cae022e02a42b82830
Author: Matthias Clasen <mclasen redhat com>
Date:   Thu Dec 3 08:37:58 2015 -0500

    Update gtk_drag_highlight() docs
    
    What they said was no longer true.

 gtk/gtkdnd.c |    7 +++----
 1 files changed, 3 insertions(+), 4 deletions(-)
---
diff --git a/gtk/gtkdnd.c b/gtk/gtkdnd.c
index 52023af..f0c8c0b 100644
--- a/gtk/gtkdnd.c
+++ b/gtk/gtkdnd.c
@@ -987,10 +987,9 @@ gtk_drag_finish (GdkDragContext *context,
  * gtk_drag_highlight: (method)
  * @widget: a widget to highlight
  *
- * Draws a highlight around a widget. This will attach
- * handlers to #GtkWidget::draw, so the highlight
- * will continue to be displayed until gtk_drag_unhighlight()
- * is called.
+ * Highlights a widget as a currently hovered drop target.
+ * To end the highlight, call gtk_drag_unhighlight().
+ * GTK+ calls this automatically if %GTK_DEST_DEFAULT_HIGHLIGHT is set.
  */
 void
 gtk_drag_highlight (GtkWidget  *widget)